About 94403 - San Mateo, California
The ZIP code 94403 of San Mateo falls within California, the United States - a densely populated area by population. It sits within San Mateo County.
Around 43,276 people live in the 94403 ZIP code area. That's noticeably above the average for a California ZIP code, which sits near 22,296 people.
Population density runs around 2,966 people per sq. mile, making it a suburban area.
Other ZIP code codes in California serve areas such as Fontana, Pittsburg, Los Angeles.